We consider a network of computer data centers on the earth surface delivering computing as a service to a big number of users. The problem is to assign users to data centers to minimize the total communication distan...We consider a network of computer data centers on the earth surface delivering computing as a service to a big number of users. The problem is to assign users to data centers to minimize the total communication distance between compu-ting resources and their users in the face of capacity constrained datacenters. In this paper, we extend the classical pla-nar Voronoi Diagram to a hyperbolic Voronoi Diagram on the sphere. We show that a solution to the distance minimi-zation problem under capacity constraints is given by a hyperbolic spherical Voronoi Diagram of data centers. We also present numerical algorithms, computer implementation and results of simulations illustrating our solution. We note applicability of our solution to other important assignment problems, including the assignment of population to regional trauma centers, location of airbases, the distribution of the telecommunication centers for mobile telephones in global telephone companies, and others.展开更多
Cloud point property was found in the aqueous mixtures of sodium dodecyl sulfate（SDS）and cetyl trimethyl ammonium bromide（CTAB）and the cloud point area in pseudo ternary plase diagram of SDS/CTAB/Na2SO4/H2O was st...Cloud point property was found in the aqueous mixtures of sodium dodecyl sulfate（SDS）and cetyl trimethyl ammonium bromide（CTAB）and the cloud point area in pseudo ternary plase diagram of SDS/CTAB/Na2SO4/H2O was studied.It was found that the cloud point area was the aqueous two-phase system area,in which the containing of SDS was more than that of CTAB.The cloud point area would enlarge when the temperature was high and the length of cationic surfactant carbochain had some effect on the position of cloud point area.展开更多
文摘We consider a network of computer data centers on the earth surface delivering computing as a service to a big number of users. The problem is to assign users to data centers to minimize the total communication distance between compu-ting resources and their users in the face of capacity constrained datacenters. In this paper, we extend the classical pla-nar Voronoi Diagram to a hyperbolic Voronoi Diagram on the sphere. We show that a solution to the distance minimi-zation problem under capacity constraints is given by a hyperbolic spherical Voronoi Diagram of data centers. We also present numerical algorithms, computer implementation and results of simulations illustrating our solution. We note applicability of our solution to other important assignment problems, including the assignment of population to regional trauma centers, location of airbases, the distribution of the telecommunication centers for mobile telephones in global telephone companies, and others.
文摘Cloud point property was found in the aqueous mixtures of sodium dodecyl sulfate（SDS）and cetyl trimethyl ammonium bromide（CTAB）and the cloud point area in pseudo ternary plase diagram of SDS/CTAB/Na2SO4/H2O was studied.It was found that the cloud point area was the aqueous two-phase system area,in which the containing of SDS was more than that of CTAB.The cloud point area would enlarge when the temperature was high and the length of cationic surfactant carbochain had some effect on the position of cloud point area.
